1. Field of the Invention
The present invention relates to a film pressing device applied to an instant photographic type image recording apparatus and, more particularly, to a film pressing device for pressing an instant film unit to an exposure station.
2. Description Related to the Prior Art
An instant photographic type image recording apparatus (hereinafter simply called an image recording apparatus) is known and used to record an image on an instant film unit as a recording medium. As the image recording apparatus, an instant printer and an instant camera are on the market, and a printer built-in electric still camera is also produced.
In the image recording apparatus, a film pack is loaded. The film pack includes a pack case and at most ten instant film units of mono sheet type (hereinafter simply called film units) which are piled up in the pack case. The image recording apparatus includes an exposure head which scans over an exposure surface of the film unit in the pack case to expose it to red, green and blue lights one by one. The film unit has a pod containing processing solution in a leading edge of the exposure surface. The exposed film unit is ejected from an ejection port of the image recording apparatus. While the film unit is squeezed through the film processing rollers, the pod is ruptured and the processing solution spreads over the film unit so that development may be made.
The image recording apparatus in the prior art has a pack chamber wherein the film pack is loaded, and a pack chamber door rotatably attached on its back side. On the inner face of the pack chamber door, the film pressing devices are attached. The film pressing device, when the pack chamber door is closed, enters into the film pack from an access opening formed on a face opposed to the exposure opening, and presses the film unit on the exposure opening. Thus, the top one of the film units keeps its exposure face flat on the exposure opening.
The film pressing device described above is disclosed for example in Japanease Patent laid-open publication number H10-39405, and includes a pressing member for contacting a film unit, a spring for biasing the pressing member to protrude in a direction perpendicular to the inner face of the pack chamber door, and a holder which holds them and is fixed on the inner face. The pressing member enters in the pack case from an access opening on its rear face and presses the film units to an exposure opening.
When the film pack contains the ten film units, the pressing member is positioned in a first contact position wherein the pressing member contacts the tenth film unit. While it is repeated to take a picture, the number of the film units remaining in the film pack is decreased. Accordingly, the pressing member shifts from the first contact to a second contact position wherein the film pack contains only the one film unit. The film pressing device, as it protrudes out perpendicular to the pack chamber door, must be longer along the protruding direction than at least the length of displacement; namely, a distance between the first and second contact positions. Further, the pressing member and the spring are arranged along the protruding direction in the holder. It is necessary to keep a space which contains the spring in pressed condition. Therefore, a gap is formed between the film pack and the pack chamber door, which increases thickness of the image recording apparatus.
A film pressing device disclosed in Japanese Patent laid-publication number 2000-10183 includes a first slide member for contacting the film unit, a spring for biasing the first slide member in a protruding direction, a second slide member which slidably secures the first slide member and protrudes in the protruding direction in accordance with the slide of the first slide member, and a holder which is fixed on an inner face of the pack chamber door disposed in the backside of the image recording apparatus and slidably secures the second slide member. In this construction, the length of each slide member along the protruding direction is about half of the displacement, and thus, becomes shorter.
However, in the film pressing device disclosed in the publication number 2000-10183, the spring and the first and second slide members are arranged in a line along the protruding direction. Therefore, a part of the holder cannot be inserted in the pack case and thus it is necessary to keep a space for it between the film pack and the pack chamber. However, as the image recording apparatus, for example the instant camera and the printer built-in electric still camera, is usually carried, it would be preferable to be slimmer.
In view of the foregoing, an object of the present invention is to provide a slimmer image recording apparatus.
Another object of the present invention is to provide an image recording apparatus in which pressure of a pressing member onto a film unit is adjusted in accordance with number of the film unit in a pack case.
The above objects and other objects are achieved by providing a pressing member rotatable between a first rotational position and a second rotational position. The pressing member is rotatably attached to a holder fixed on an inner face of a pack chamber door. When the pack chamber door is closed, the pressing member is inserted into the pack case from an access opening. While the pressing member rotates to the second rotational position, a pressing portion thereof presses a rear face of the film unit which is the lowest in the pack case.
In the preferred embodiment of the present invention, a biasing member has a first torsion spring whose force is weak, and a second torsion spring whose force is strong. The first torsion spring biases the pressing member from the first rotational position to a third rotational position, and the second torsion spring biases the pressing member from the first rotational position to the second rotational position. The third rotational position is between the first rotational position and a second rotational position.
In the more preferred embodiment of the invention, plural of the film pressing devices are attached on the pack chamber door, and presses the film unit. The film pressing device has two pressure levers whose rotational directions are opposite to each other.
In other embodiments, the film pressing device is provided with rotatable first and second pressure levers. The middle portions of the first and second pressure levers are connected by a pin fitting in a long hole. Ends of the first and second pressure levers are connected with a pressure plate. The pressure plate is inserted in the pack case from the access opening, and presses the rear face of the film unit which is the lowest in the pack case.
According to the invention, as the pressing member is rotatable, it is provided in a small space for the film pressing device, which makes the image recording apparatus slimmer. Further, as the first torsion spring and the second torsion spring are used, the pressure is adjusted corresponding to the number of the film units in the pack case. Therefore, the film units are neither broken nor ruptured, even if the number is under a predetermined one.